Small difference equating to a big difference?

My system had started to sound a bit dull and lifeless to me ever since I put in some blue jeans interconnects. I'm getting a lightspeed attenuator in a week or two so I purchased two pairs of short, inexpensive interconnects with a really low rated capacitance in order to use them with the lightspeed. Anyways, I replaced a pair of audioquest diamond back rca's between my dac and pre, and a pair of signal cable silver resolution xlr's between my amp and pre amp with the blue jeans so that I could have them broken in by the time the lightspeed gets here.
Anyhow, my system had, what I thought, lost a lot of detail and "life" and couldn't really figure out exactly why. So I grabbed two pairs of analysis plus oval interconnects to demo tonight and voila, right from the first song, I had my detail and "life" back. When I a/b compared them to the blue jeans I couldn't spot big differences like I thought I'd be able to, but for some reason it does in fact sound like a big difference and I can't put my finger, errrr, ear on it. The analysis plus do have slightly more detail and sound slightly more fleshed out but the don't sound day and night different but they do; does that make sense to anyone?
At the end, I a/b compared the original diamond back from dac to pre, signal cable silver res xlr between the pre and amp to the analysis plus between dac and pre and also between pre and amp. The diamond back / signal set up had more bass and equaled the analysis plus in all other areas but for some reason I still slightly prefer the analysis plus.

I've found also that sometimes it's hard for me to give a product an honest assesment if I've read reviews on the product before I listen to it because I'll be anticipate hearing the pros and cons about that product before I even begin to listen.

So what do you think is going on here with such perceived slight differences making a bigger difference? Is it possible I'm picking up on things in the sound that I'm not consciously aware of analysing like tone or prat?